This invention relates to a steering column jacket, and more particularly, to a steering column jacket having a composite structure including a foam material.
Generally, beamed structures are used to support a steering column structure. The beams, often referred to as steering column jackets, are metal tubes having sufficient strength to support the forces encountered during a vehicle collision. Current jackets are generally manufactured from either of two metal-forming processes, including welding stampings and tubings, as well as utilizing cast metal parts. The metal jackets are designed with the necessary strength to support the forces exerted during a vehicle collision, however, further improvement, including reducing the overall weight and improving strength characteristics is desirable.
Also, an improvement of a steering column jacket to dampen vibrations produced during travel over rough roads would be desirable. By eliminating a portion of the weight of conventional steering metal column jackets, an overall weight reduction to a vehicle may be achieved yielding a higher gas mileage.
There is therefore a need for a composite steering column jacket that is lighter in weight when compared with metal steering column jackets, and has improved dampening characteristics, without a sacrifice in strength.
A composite steering column jacket including a pair of composite sections joined along a flange area. The composite sections are formed of an outer wall having inner and outer surfaces. The outer wall also includes a first flange formed thereon. An inner wall having inner and outer surfaces is spaced coaxially from the outer wall. The inner wall also includes a second flange that mates with the first flange of the outer wall. A cavity defined by the space between the inner surface of the outer wall and the outer surface of the inner wall has foam material disposed within. The composite steering column jacket has an increased stiffness and reduced weight in comparison to a conventional metal steering column jacket.
In an alternative embodiment, an aluminum foam is attached to the outer surfaces of the inner and outer walls to strengthen the overall structure of the composite steering column jacket, in lieu of the foam contained within the cavity